It would be very useful if you were asking the right question. The storage facility from the article has a 750 MW storage capacity (energy) which it can deliver at a max output (power) of 3000 MW/hr Power plant and storage facility capacities are measured in MW since what they are intended to do is supply power at a steady rate. Who cares if you can store a billion TW of power if you can only output it at 5mW/h. It does no good if you can’t get it out. Supply is what we really care about here.
This guy gets it.